Signal lamps won't flash. Why?

[Roger W.]

Re: Signal lamps won't flash. Why?

I really would not suspect a poor ground if your directional lights illuminate brightly. I would connect the flasher to a bulb on the bench with a 12 volt supply. If you have one of those emergency jumper supplies, that would work. Polarity on the flasher should not matter. The flasher is just a coil that heats up with the current running through it which causes the bi metal contacts to open. when the coil cools off the contacts close. The cycle repeats as long as voltage is applied.

[Kevin P.]

Re: Signal lamps won't flash. Why?

Roger, If you read post # 8 Perry states the outer lamp is bright and the inner is dim that sounds like a GROUND problem. Kevin (775)

[John D.]

Re: Signal lamps won't flash. Why?

In FI restorations I am using a DC power supply for testing. Regular output voltage can be regulated to 0-18V. Regular output current is 0-3A
I use it to test siphon breaker solenoids, choke covers, starting solenoids, etc. It could also be used to test the turn signal flashers of course.
In the old days when I played with Model A Fords a test light was the tool to use. But not today.
When I was a commercial builder i had my electrician buy me a first class expensive digital tester. Price was right.(free)
But as mentioned you can pick up a digital tester at Radio Shack or Walmarts for just a few bucks.
As mentioned by several of you one of the big problems with Corvettes = getting a good ground. A nice long wire with alligator clips on it comes in handy.

[Perry M.]

Re: Signal lamps won't flash. Why?

The mystery is solved. It was a grounding issue, actually two grounding issues. The right inboard lamp had a bad connection where the white/black ground wire was attached to the stud. The left side was a little more complex. I did what Michael Hanson suggested, grounded the chrome part of the lamp housing to the bumper. When I did that, it made no difference but when I grounded the inner portion of the lamp, which would be the cad plated portion, the bulb flashed. There was insufficient contact between the two pieces of the lamp housing. Has anybody got a suggestion for making a good contact between these two pieces? If I tighten the lens screw it works but I'm afraid that the lens will crack from too much pressure.

[Perry M.]

Re: Signal lamps won't flash. Why?

Perry, If you find that a 552 flasher works I can send you another NOS #143 flasher just send it back and i will send you another. Kevin (775)

Hi Kevin. The flashers, my original and your replacement, are both fine. I will keep yours in my spare parts box but thanks for the offer.

[Michael H.]

Re: Signal lamps won't flash. Why?

The mystery is solved. It was a grounding issue, actually two grounding issues.

Perry,

The problem that you described is actually quite common, especially for Corvettes because of the additional ground wire required for the fiberglass body. That's why I knew it was most likely a poor ground issue.

Turn signal flashers require a specific range of resistance/load to function properly. Not enough resistance and they won't cycle. That's why there's a different part/number flasher for 2 lamp and three lamp systems.

[Roger W.]

Re: Signal lamps won't flash. Why?

You are correct Kevin. I did not catch the dim bulb description on Perry's 2nd post.

[Dale M.]

Re: Signal lamps won't flash. Why?

Monte, Just hooking up a flasher to 12V put a very large load on the flasher? Arn't they intended to have the resistance of the light bulbs and some wiring? Ihave several old flasher that I would lilke to check. Thabnks